xref: /openbmc/linux/kernel/irq/irqdesc.c (revision 62e59c4e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
4  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
5  *
6  * This file contains the interrupt descriptor management code. Detailed
7  * information is available in Documentation/core-api/genericirq.rst
8  *
9  */
10 #include <linux/irq.h>
11 #include <linux/slab.h>
12 #include <linux/export.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/radix-tree.h>
16 #include <linux/bitmap.h>
17 #include <linux/irqdomain.h>
18 #include <linux/sysfs.h>
19 
20 #include "internals.h"
21 
22 /*
23  * lockdep: we want to handle all irq_desc locks as a single lock-class:
24  */
25 static struct lock_class_key irq_desc_lock_class;
26 
27 #if defined(CONFIG_SMP)
28 static int __init irq_affinity_setup(char *str)
29 {
30 	alloc_bootmem_cpumask_var(&irq_default_affinity);
31 	cpulist_parse(str, irq_default_affinity);
32 	/*
33 	 * Set at least the boot cpu. We don't want to end up with
34 	 * bugreports caused by random comandline masks
35 	 */
36 	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
37 	return 1;
38 }
39 __setup("irqaffinity=", irq_affinity_setup);
40 
41 static void __init init_irq_default_affinity(void)
42 {
43 	if (!cpumask_available(irq_default_affinity))
44 		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
45 	if (cpumask_empty(irq_default_affinity))
46 		cpumask_setall(irq_default_affinity);
47 }
48 #else
49 static void __init init_irq_default_affinity(void)
50 {
51 }
52 #endif
53 
54 #ifdef CONFIG_SMP
55 static int alloc_masks(struct irq_desc *desc, int node)
56 {
57 	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
58 				     GFP_KERNEL, node))
59 		return -ENOMEM;
60 
61 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
62 	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
63 				     GFP_KERNEL, node)) {
64 		free_cpumask_var(desc->irq_common_data.affinity);
65 		return -ENOMEM;
66 	}
67 #endif
68 
69 #ifdef CONFIG_GENERIC_PENDING_IRQ
70 	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
71 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
72 		free_cpumask_var(desc->irq_common_data.effective_affinity);
73 #endif
74 		free_cpumask_var(desc->irq_common_data.affinity);
75 		return -ENOMEM;
76 	}
77 #endif
78 	return 0;
79 }
80 
81 static void desc_smp_init(struct irq_desc *desc, int node,
82 			  const struct cpumask *affinity)
83 {
84 	if (!affinity)
85 		affinity = irq_default_affinity;
86 	cpumask_copy(desc->irq_common_data.affinity, affinity);
87 
88 #ifdef CONFIG_GENERIC_PENDING_IRQ
89 	cpumask_clear(desc->pending_mask);
90 #endif
91 #ifdef CONFIG_NUMA
92 	desc->irq_common_data.node = node;
93 #endif
94 }
95 
96 #else
97 static inline int
98 alloc_masks(struct irq_desc *desc, int node) { return 0; }
99 static inline void
100 desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
101 #endif
102 
103 static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
104 			      const struct cpumask *affinity, struct module *owner)
105 {
106 	int cpu;
107 
108 	desc->irq_common_data.handler_data = NULL;
109 	desc->irq_common_data.msi_desc = NULL;
110 
111 	desc->irq_data.common = &desc->irq_common_data;
112 	desc->irq_data.irq = irq;
113 	desc->irq_data.chip = &no_irq_chip;
114 	desc->irq_data.chip_data = NULL;
115 	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
116 	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
117 	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
118 	desc->handle_irq = handle_bad_irq;
119 	desc->depth = 1;
120 	desc->irq_count = 0;
121 	desc->irqs_unhandled = 0;
122 	desc->tot_count = 0;
123 	desc->name = NULL;
124 	desc->owner = owner;
125 	for_each_possible_cpu(cpu)
126 		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
127 	desc_smp_init(desc, node, affinity);
128 }
129 
130 int nr_irqs = NR_IRQS;
131 EXPORT_SYMBOL_GPL(nr_irqs);
132 
133 static DEFINE_MUTEX(sparse_irq_lock);
134 static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
135 
136 #ifdef CONFIG_SPARSE_IRQ
137 
138 static void irq_kobj_release(struct kobject *kobj);
139 
140 #ifdef CONFIG_SYSFS
141 static struct kobject *irq_kobj_base;
142 
143 #define IRQ_ATTR_RO(_name) \
144 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
145 
146 static ssize_t per_cpu_count_show(struct kobject *kobj,
147 				  struct kobj_attribute *attr, char *buf)
148 {
149 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
150 	int cpu, irq = desc->irq_data.irq;
151 	ssize_t ret = 0;
152 	char *p = "";
153 
154 	for_each_possible_cpu(cpu) {
155 		unsigned int c = kstat_irqs_cpu(irq, cpu);
156 
157 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
158 		p = ",";
159 	}
160 
161 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
162 	return ret;
163 }
164 IRQ_ATTR_RO(per_cpu_count);
165 
166 static ssize_t chip_name_show(struct kobject *kobj,
167 			      struct kobj_attribute *attr, char *buf)
168 {
169 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
170 	ssize_t ret = 0;
171 
172 	raw_spin_lock_irq(&desc->lock);
173 	if (desc->irq_data.chip && desc->irq_data.chip->name) {
174 		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
175 				desc->irq_data.chip->name);
176 	}
177 	raw_spin_unlock_irq(&desc->lock);
178 
179 	return ret;
180 }
181 IRQ_ATTR_RO(chip_name);
182 
183 static ssize_t hwirq_show(struct kobject *kobj,
184 			  struct kobj_attribute *attr, char *buf)
185 {
186 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
187 	ssize_t ret = 0;
188 
189 	raw_spin_lock_irq(&desc->lock);
190 	if (desc->irq_data.domain)
191 		ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
192 	raw_spin_unlock_irq(&desc->lock);
193 
194 	return ret;
195 }
196 IRQ_ATTR_RO(hwirq);
197 
198 static ssize_t type_show(struct kobject *kobj,
199 			 struct kobj_attribute *attr, char *buf)
200 {
201 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
202 	ssize_t ret = 0;
203 
204 	raw_spin_lock_irq(&desc->lock);
205 	ret = sprintf(buf, "%s\n",
206 		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
207 	raw_spin_unlock_irq(&desc->lock);
208 
209 	return ret;
210 
211 }
212 IRQ_ATTR_RO(type);
213 
214 static ssize_t wakeup_show(struct kobject *kobj,
215 			   struct kobj_attribute *attr, char *buf)
216 {
217 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
218 	ssize_t ret = 0;
219 
220 	raw_spin_lock_irq(&desc->lock);
221 	ret = sprintf(buf, "%s\n",
222 		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
223 	raw_spin_unlock_irq(&desc->lock);
224 
225 	return ret;
226 
227 }
228 IRQ_ATTR_RO(wakeup);
229 
230 static ssize_t name_show(struct kobject *kobj,
231 			 struct kobj_attribute *attr, char *buf)
232 {
233 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
234 	ssize_t ret = 0;
235 
236 	raw_spin_lock_irq(&desc->lock);
237 	if (desc->name)
238 		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
239 	raw_spin_unlock_irq(&desc->lock);
240 
241 	return ret;
242 }
243 IRQ_ATTR_RO(name);
244 
245 static ssize_t actions_show(struct kobject *kobj,
246 			    struct kobj_attribute *attr, char *buf)
247 {
248 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
249 	struct irqaction *action;
250 	ssize_t ret = 0;
251 	char *p = "";
252 
253 	raw_spin_lock_irq(&desc->lock);
254 	for (action = desc->action; action != NULL; action = action->next) {
255 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
256 				 p, action->name);
257 		p = ",";
258 	}
259 	raw_spin_unlock_irq(&desc->lock);
260 
261 	if (ret)
262 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
263 
264 	return ret;
265 }
266 IRQ_ATTR_RO(actions);
267 
268 static struct attribute *irq_attrs[] = {
269 	&per_cpu_count_attr.attr,
270 	&chip_name_attr.attr,
271 	&hwirq_attr.attr,
272 	&type_attr.attr,
273 	&wakeup_attr.attr,
274 	&name_attr.attr,
275 	&actions_attr.attr,
276 	NULL
277 };
278 
279 static struct kobj_type irq_kobj_type = {
280 	.release	= irq_kobj_release,
281 	.sysfs_ops	= &kobj_sysfs_ops,
282 	.default_attrs	= irq_attrs,
283 };
284 
285 static void irq_sysfs_add(int irq, struct irq_desc *desc)
286 {
287 	if (irq_kobj_base) {
288 		/*
289 		 * Continue even in case of failure as this is nothing
290 		 * crucial.
291 		 */
292 		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
293 			pr_warn("Failed to add kobject for irq %d\n", irq);
294 	}
295 }
296 
297 static int __init irq_sysfs_init(void)
298 {
299 	struct irq_desc *desc;
300 	int irq;
301 
302 	/* Prevent concurrent irq alloc/free */
303 	irq_lock_sparse();
304 
305 	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
306 	if (!irq_kobj_base) {
307 		irq_unlock_sparse();
308 		return -ENOMEM;
309 	}
310 
311 	/* Add the already allocated interrupts */
312 	for_each_irq_desc(irq, desc)
313 		irq_sysfs_add(irq, desc);
314 	irq_unlock_sparse();
315 
316 	return 0;
317 }
318 postcore_initcall(irq_sysfs_init);
319 
320 #else /* !CONFIG_SYSFS */
321 
322 static struct kobj_type irq_kobj_type = {
323 	.release	= irq_kobj_release,
324 };
325 
326 static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
327 
328 #endif /* CONFIG_SYSFS */
329 
330 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
331 
332 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
333 {
334 	radix_tree_insert(&irq_desc_tree, irq, desc);
335 }
336 
337 struct irq_desc *irq_to_desc(unsigned int irq)
338 {
339 	return radix_tree_lookup(&irq_desc_tree, irq);
340 }
341 EXPORT_SYMBOL(irq_to_desc);
342 
343 static void delete_irq_desc(unsigned int irq)
344 {
345 	radix_tree_delete(&irq_desc_tree, irq);
346 }
347 
348 #ifdef CONFIG_SMP
349 static void free_masks(struct irq_desc *desc)
350 {
351 #ifdef CONFIG_GENERIC_PENDING_IRQ
352 	free_cpumask_var(desc->pending_mask);
353 #endif
354 	free_cpumask_var(desc->irq_common_data.affinity);
355 #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
356 	free_cpumask_var(desc->irq_common_data.effective_affinity);
357 #endif
358 }
359 #else
360 static inline void free_masks(struct irq_desc *desc) { }
361 #endif
362 
363 void irq_lock_sparse(void)
364 {
365 	mutex_lock(&sparse_irq_lock);
366 }
367 
368 void irq_unlock_sparse(void)
369 {
370 	mutex_unlock(&sparse_irq_lock);
371 }
372 
373 static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
374 				   const struct cpumask *affinity,
375 				   struct module *owner)
376 {
377 	struct irq_desc *desc;
378 
379 	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
380 	if (!desc)
381 		return NULL;
382 	/* allocate based on nr_cpu_ids */
383 	desc->kstat_irqs = alloc_percpu(unsigned int);
384 	if (!desc->kstat_irqs)
385 		goto err_desc;
386 
387 	if (alloc_masks(desc, node))
388 		goto err_kstat;
389 
390 	raw_spin_lock_init(&desc->lock);
391 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
392 	mutex_init(&desc->request_mutex);
393 	init_rcu_head(&desc->rcu);
394 
395 	desc_set_defaults(irq, desc, node, affinity, owner);
396 	irqd_set(&desc->irq_data, flags);
397 	kobject_init(&desc->kobj, &irq_kobj_type);
398 
399 	return desc;
400 
401 err_kstat:
402 	free_percpu(desc->kstat_irqs);
403 err_desc:
404 	kfree(desc);
405 	return NULL;
406 }
407 
408 static void irq_kobj_release(struct kobject *kobj)
409 {
410 	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
411 
412 	free_masks(desc);
413 	free_percpu(desc->kstat_irqs);
414 	kfree(desc);
415 }
416 
417 static void delayed_free_desc(struct rcu_head *rhp)
418 {
419 	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
420 
421 	kobject_put(&desc->kobj);
422 }
423 
424 static void free_desc(unsigned int irq)
425 {
426 	struct irq_desc *desc = irq_to_desc(irq);
427 
428 	irq_remove_debugfs_entry(desc);
429 	unregister_irq_proc(irq, desc);
430 
431 	/*
432 	 * sparse_irq_lock protects also show_interrupts() and
433 	 * kstat_irq_usr(). Once we deleted the descriptor from the
434 	 * sparse tree we can free it. Access in proc will fail to
435 	 * lookup the descriptor.
436 	 *
437 	 * The sysfs entry must be serialized against a concurrent
438 	 * irq_sysfs_init() as well.
439 	 */
440 	kobject_del(&desc->kobj);
441 	delete_irq_desc(irq);
442 
443 	/*
444 	 * We free the descriptor, masks and stat fields via RCU. That
445 	 * allows demultiplex interrupts to do rcu based management of
446 	 * the child interrupts.
447 	 * This also allows us to use rcu in kstat_irqs_usr().
448 	 */
449 	call_rcu(&desc->rcu, delayed_free_desc);
450 }
451 
452 static int alloc_descs(unsigned int start, unsigned int cnt, int node,
453 		       const struct irq_affinity_desc *affinity,
454 		       struct module *owner)
455 {
456 	struct irq_desc *desc;
457 	int i;
458 
459 	/* Validate affinity mask(s) */
460 	if (affinity) {
461 		for (i = 0; i < cnt; i++) {
462 			if (cpumask_empty(&affinity[i].mask))
463 				return -EINVAL;
464 		}
465 	}
466 
467 	for (i = 0; i < cnt; i++) {
468 		const struct cpumask *mask = NULL;
469 		unsigned int flags = 0;
470 
471 		if (affinity) {
472 			if (affinity->is_managed) {
473 				flags = IRQD_AFFINITY_MANAGED |
474 					IRQD_MANAGED_SHUTDOWN;
475 			}
476 			mask = &affinity->mask;
477 			node = cpu_to_node(cpumask_first(mask));
478 			affinity++;
479 		}
480 
481 		desc = alloc_desc(start + i, node, flags, mask, owner);
482 		if (!desc)
483 			goto err;
484 		irq_insert_desc(start + i, desc);
485 		irq_sysfs_add(start + i, desc);
486 		irq_add_debugfs_entry(start + i, desc);
487 	}
488 	bitmap_set(allocated_irqs, start, cnt);
489 	return start;
490 
491 err:
492 	for (i--; i >= 0; i--)
493 		free_desc(start + i);
494 	return -ENOMEM;
495 }
496 
497 static int irq_expand_nr_irqs(unsigned int nr)
498 {
499 	if (nr > IRQ_BITMAP_BITS)
500 		return -ENOMEM;
501 	nr_irqs = nr;
502 	return 0;
503 }
504 
505 int __init early_irq_init(void)
506 {
507 	int i, initcnt, node = first_online_node;
508 	struct irq_desc *desc;
509 
510 	init_irq_default_affinity();
511 
512 	/* Let arch update nr_irqs and return the nr of preallocated irqs */
513 	initcnt = arch_probe_nr_irqs();
514 	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
515 	       NR_IRQS, nr_irqs, initcnt);
516 
517 	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
518 		nr_irqs = IRQ_BITMAP_BITS;
519 
520 	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
521 		initcnt = IRQ_BITMAP_BITS;
522 
523 	if (initcnt > nr_irqs)
524 		nr_irqs = initcnt;
525 
526 	for (i = 0; i < initcnt; i++) {
527 		desc = alloc_desc(i, node, 0, NULL, NULL);
528 		set_bit(i, allocated_irqs);
529 		irq_insert_desc(i, desc);
530 	}
531 	return arch_early_irq_init();
532 }
533 
534 #else /* !CONFIG_SPARSE_IRQ */
535 
536 struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
537 	[0 ... NR_IRQS-1] = {
538 		.handle_irq	= handle_bad_irq,
539 		.depth		= 1,
540 		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
541 	}
542 };
543 
544 int __init early_irq_init(void)
545 {
546 	int count, i, node = first_online_node;
547 	struct irq_desc *desc;
548 
549 	init_irq_default_affinity();
550 
551 	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
552 
553 	desc = irq_desc;
554 	count = ARRAY_SIZE(irq_desc);
555 
556 	for (i = 0; i < count; i++) {
557 		desc[i].kstat_irqs = alloc_percpu(unsigned int);
558 		alloc_masks(&desc[i], node);
559 		raw_spin_lock_init(&desc[i].lock);
560 		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
561 		mutex_init(&desc[i].request_mutex);
562 		desc_set_defaults(i, &desc[i], node, NULL, NULL);
563 	}
564 	return arch_early_irq_init();
565 }
566 
567 struct irq_desc *irq_to_desc(unsigned int irq)
568 {
569 	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
570 }
571 EXPORT_SYMBOL(irq_to_desc);
572 
573 static void free_desc(unsigned int irq)
574 {
575 	struct irq_desc *desc = irq_to_desc(irq);
576 	unsigned long flags;
577 
578 	raw_spin_lock_irqsave(&desc->lock, flags);
579 	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
580 	raw_spin_unlock_irqrestore(&desc->lock, flags);
581 }
582 
583 static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
584 			      const struct irq_affinity_desc *affinity,
585 			      struct module *owner)
586 {
587 	u32 i;
588 
589 	for (i = 0; i < cnt; i++) {
590 		struct irq_desc *desc = irq_to_desc(start + i);
591 
592 		desc->owner = owner;
593 	}
594 	bitmap_set(allocated_irqs, start, cnt);
595 	return start;
596 }
597 
598 static int irq_expand_nr_irqs(unsigned int nr)
599 {
600 	return -ENOMEM;
601 }
602 
603 void irq_mark_irq(unsigned int irq)
604 {
605 	mutex_lock(&sparse_irq_lock);
606 	bitmap_set(allocated_irqs, irq, 1);
607 	mutex_unlock(&sparse_irq_lock);
608 }
609 
610 #ifdef CONFIG_GENERIC_IRQ_LEGACY
611 void irq_init_desc(unsigned int irq)
612 {
613 	free_desc(irq);
614 }
615 #endif
616 
617 #endif /* !CONFIG_SPARSE_IRQ */
618 
619 /**
620  * generic_handle_irq - Invoke the handler for a particular irq
621  * @irq:	The irq number to handle
622  *
623  */
624 int generic_handle_irq(unsigned int irq)
625 {
626 	struct irq_desc *desc = irq_to_desc(irq);
627 
628 	if (!desc)
629 		return -EINVAL;
630 	generic_handle_irq_desc(desc);
631 	return 0;
632 }
633 EXPORT_SYMBOL_GPL(generic_handle_irq);
634 
635 #ifdef CONFIG_HANDLE_DOMAIN_IRQ
636 /**
637  * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
638  * @domain:	The domain where to perform the lookup
639  * @hwirq:	The HW irq number to convert to a logical one
640  * @lookup:	Whether to perform the domain lookup or not
641  * @regs:	Register file coming from the low-level handling code
642  *
643  * Returns:	0 on success, or -EINVAL if conversion has failed
644  */
645 int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
646 			bool lookup, struct pt_regs *regs)
647 {
648 	struct pt_regs *old_regs = set_irq_regs(regs);
649 	unsigned int irq = hwirq;
650 	int ret = 0;
651 
652 	irq_enter();
653 
654 #ifdef CONFIG_IRQ_DOMAIN
655 	if (lookup)
656 		irq = irq_find_mapping(domain, hwirq);
657 #endif
658 
659 	/*
660 	 * Some hardware gives randomly wrong interrupts.  Rather
661 	 * than crashing, do something sensible.
662 	 */
663 	if (unlikely(!irq || irq >= nr_irqs)) {
664 		ack_bad_irq(irq);
665 		ret = -EINVAL;
666 	} else {
667 		generic_handle_irq(irq);
668 	}
669 
670 	irq_exit();
671 	set_irq_regs(old_regs);
672 	return ret;
673 }
674 
675 #ifdef CONFIG_IRQ_DOMAIN
676 /**
677  * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain
678  * @domain:	The domain where to perform the lookup
679  * @hwirq:	The HW irq number to convert to a logical one
680  * @regs:	Register file coming from the low-level handling code
681  *
682  * Returns:	0 on success, or -EINVAL if conversion has failed
683  */
684 int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
685 		      struct pt_regs *regs)
686 {
687 	struct pt_regs *old_regs = set_irq_regs(regs);
688 	unsigned int irq;
689 	int ret = 0;
690 
691 	nmi_enter();
692 
693 	irq = irq_find_mapping(domain, hwirq);
694 
695 	/*
696 	 * ack_bad_irq is not NMI-safe, just report
697 	 * an invalid interrupt.
698 	 */
699 	if (likely(irq))
700 		generic_handle_irq(irq);
701 	else
702 		ret = -EINVAL;
703 
704 	nmi_exit();
705 	set_irq_regs(old_regs);
706 	return ret;
707 }
708 #endif
709 #endif
710 
711 /* Dynamic interrupt handling */
712 
713 /**
714  * irq_free_descs - free irq descriptors
715  * @from:	Start of descriptor range
716  * @cnt:	Number of consecutive irqs to free
717  */
718 void irq_free_descs(unsigned int from, unsigned int cnt)
719 {
720 	int i;
721 
722 	if (from >= nr_irqs || (from + cnt) > nr_irqs)
723 		return;
724 
725 	mutex_lock(&sparse_irq_lock);
726 	for (i = 0; i < cnt; i++)
727 		free_desc(from + i);
728 
729 	bitmap_clear(allocated_irqs, from, cnt);
730 	mutex_unlock(&sparse_irq_lock);
731 }
732 EXPORT_SYMBOL_GPL(irq_free_descs);
733 
734 /**
735  * irq_alloc_descs - allocate and initialize a range of irq descriptors
736  * @irq:	Allocate for specific irq number if irq >= 0
737  * @from:	Start the search from this irq number
738  * @cnt:	Number of consecutive irqs to allocate.
739  * @node:	Preferred node on which the irq descriptor should be allocated
740  * @owner:	Owning module (can be NULL)
741  * @affinity:	Optional pointer to an affinity mask array of size @cnt which
742  *		hints where the irq descriptors should be allocated and which
743  *		default affinities to use
744  *
745  * Returns the first irq number or error code
746  */
747 int __ref
748 __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
749 		  struct module *owner, const struct irq_affinity_desc *affinity)
750 {
751 	int start, ret;
752 
753 	if (!cnt)
754 		return -EINVAL;
755 
756 	if (irq >= 0) {
757 		if (from > irq)
758 			return -EINVAL;
759 		from = irq;
760 	} else {
761 		/*
762 		 * For interrupts which are freely allocated the
763 		 * architecture can force a lower bound to the @from
764 		 * argument. x86 uses this to exclude the GSI space.
765 		 */
766 		from = arch_dynirq_lower_bound(from);
767 	}
768 
769 	mutex_lock(&sparse_irq_lock);
770 
771 	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
772 					   from, cnt, 0);
773 	ret = -EEXIST;
774 	if (irq >=0 && start != irq)
775 		goto unlock;
776 
777 	if (start + cnt > nr_irqs) {
778 		ret = irq_expand_nr_irqs(start + cnt);
779 		if (ret)
780 			goto unlock;
781 	}
782 	ret = alloc_descs(start, cnt, node, affinity, owner);
783 unlock:
784 	mutex_unlock(&sparse_irq_lock);
785 	return ret;
786 }
787 EXPORT_SYMBOL_GPL(__irq_alloc_descs);
788 
789 #ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
790 /**
791  * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
792  * @cnt:	number of interrupts to allocate
793  * @node:	node on which to allocate
794  *
795  * Returns an interrupt number > 0 or 0, if the allocation fails.
796  */
797 unsigned int irq_alloc_hwirqs(int cnt, int node)
798 {
799 	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);
800 
801 	if (irq < 0)
802 		return 0;
803 
804 	for (i = irq; cnt > 0; i++, cnt--) {
805 		if (arch_setup_hwirq(i, node))
806 			goto err;
807 		irq_clear_status_flags(i, _IRQ_NOREQUEST);
808 	}
809 	return irq;
810 
811 err:
812 	for (i--; i >= irq; i--) {
813 		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
814 		arch_teardown_hwirq(i);
815 	}
816 	irq_free_descs(irq, cnt);
817 	return 0;
818 }
819 EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);
820 
821 /**
822  * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
823  * @from:	Free from irq number
824  * @cnt:	number of interrupts to free
825  *
826  */
827 void irq_free_hwirqs(unsigned int from, int cnt)
828 {
829 	int i, j;
830 
831 	for (i = from, j = cnt; j > 0; i++, j--) {
832 		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
833 		arch_teardown_hwirq(i);
834 	}
835 	irq_free_descs(from, cnt);
836 }
837 EXPORT_SYMBOL_GPL(irq_free_hwirqs);
838 #endif
839 
840 /**
841  * irq_get_next_irq - get next allocated irq number
842  * @offset:	where to start the search
843  *
844  * Returns next irq number after offset or nr_irqs if none is found.
845  */
846 unsigned int irq_get_next_irq(unsigned int offset)
847 {
848 	return find_next_bit(allocated_irqs, nr_irqs, offset);
849 }
850 
851 struct irq_desc *
852 __irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
853 		    unsigned int check)
854 {
855 	struct irq_desc *desc = irq_to_desc(irq);
856 
857 	if (desc) {
858 		if (check & _IRQ_DESC_CHECK) {
859 			if ((check & _IRQ_DESC_PERCPU) &&
860 			    !irq_settings_is_per_cpu_devid(desc))
861 				return NULL;
862 
863 			if (!(check & _IRQ_DESC_PERCPU) &&
864 			    irq_settings_is_per_cpu_devid(desc))
865 				return NULL;
866 		}
867 
868 		if (bus)
869 			chip_bus_lock(desc);
870 		raw_spin_lock_irqsave(&desc->lock, *flags);
871 	}
872 	return desc;
873 }
874 
875 void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
876 {
877 	raw_spin_unlock_irqrestore(&desc->lock, flags);
878 	if (bus)
879 		chip_bus_sync_unlock(desc);
880 }
881 
882 int irq_set_percpu_devid_partition(unsigned int irq,
883 				   const struct cpumask *affinity)
884 {
885 	struct irq_desc *desc = irq_to_desc(irq);
886 
887 	if (!desc)
888 		return -EINVAL;
889 
890 	if (desc->percpu_enabled)
891 		return -EINVAL;
892 
893 	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);
894 
895 	if (!desc->percpu_enabled)
896 		return -ENOMEM;
897 
898 	if (affinity)
899 		desc->percpu_affinity = affinity;
900 	else
901 		desc->percpu_affinity = cpu_possible_mask;
902 
903 	irq_set_percpu_devid_flags(irq);
904 	return 0;
905 }
906 
907 int irq_set_percpu_devid(unsigned int irq)
908 {
909 	return irq_set_percpu_devid_partition(irq, NULL);
910 }
911 
912 int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
913 {
914 	struct irq_desc *desc = irq_to_desc(irq);
915 
916 	if (!desc || !desc->percpu_enabled)
917 		return -EINVAL;
918 
919 	if (affinity)
920 		cpumask_copy(affinity, desc->percpu_affinity);
921 
922 	return 0;
923 }
924 EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
925 
926 void kstat_incr_irq_this_cpu(unsigned int irq)
927 {
928 	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
929 }
930 
931 /**
932  * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
933  * @irq:	The interrupt number
934  * @cpu:	The cpu number
935  *
936  * Returns the sum of interrupt counts on @cpu since boot for
937  * @irq. The caller must ensure that the interrupt is not removed
938  * concurrently.
939  */
940 unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
941 {
942 	struct irq_desc *desc = irq_to_desc(irq);
943 
944 	return desc && desc->kstat_irqs ?
945 			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
946 }
947 
948 /**
949  * kstat_irqs - Get the statistics for an interrupt
950  * @irq:	The interrupt number
951  *
952  * Returns the sum of interrupt counts on all cpus since boot for
953  * @irq. The caller must ensure that the interrupt is not removed
954  * concurrently.
955  */
956 unsigned int kstat_irqs(unsigned int irq)
957 {
958 	struct irq_desc *desc = irq_to_desc(irq);
959 	unsigned int sum = 0;
960 	int cpu;
961 
962 	if (!desc || !desc->kstat_irqs)
963 		return 0;
964 	if (!irq_settings_is_per_cpu_devid(desc) &&
965 	    !irq_settings_is_per_cpu(desc))
966 	    return desc->tot_count;
967 
968 	for_each_possible_cpu(cpu)
969 		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
970 	return sum;
971 }
972 
973 /**
974  * kstat_irqs_usr - Get the statistics for an interrupt
975  * @irq:	The interrupt number
976  *
977  * Returns the sum of interrupt counts on all cpus since boot for @irq.
978  * Contrary to kstat_irqs() this can be called from any context.
979  * It uses rcu since a concurrent removal of an interrupt descriptor is
980  * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
981  */
982 unsigned int kstat_irqs_usr(unsigned int irq)
983 {
984 	unsigned int sum;
985 
986 	rcu_read_lock();
987 	sum = kstat_irqs(irq);
988 	rcu_read_unlock();
989 	return sum;
990 }
991